1 files changed, 108 insertions, 0 deletions
diff --git a/src/lib/analyse_audio_job.cc b/src/lib/analyse_audio_job.cc
new file mode 100644
index 000000000..5623fdfcc
--- /dev/null
+++ b/src/lib/analyse_audio_job.cc
@@ -0,0 +1,108 @@
+/*
+    Copyright (C) 2012 Carl Hetherington <cth@carlh.net>
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include "audio_analysis.h"
+#include "analyse_audio_job.h"
+#include "compose.hpp"
+#include "film.h"
+#include "options.h"
+#include "decoder_factory.h"
+#include "audio_decoder.h"
+
+using std::string;
+using std::max;
+using boost::shared_ptr;
+
+int const AnalyseAudioJob::_num_points = 1024;
+
+AnalyseAudioJob::AnalyseAudioJob (shared_ptr<Film> f)
+	: Job (f)
+	, _done_for_this_point (0)
+	, _done (0)
+	, _samples_per_point (1)
+{
+
+}
+
+string
+AnalyseAudioJob::name () const
+{
+	return String::compose ("Analyse audio of %1", _film->name());
+}
+
+void
+AnalyseAudioJob::run ()
+{
+	if (!_film->audio_stream () || !_film->length()) {
+		set_progress (1);
+		set_state (FINISHED_ERROR);
+		return;
+	}
+		
+	DecodeOptions options;
+	options.decode_video = false;
+
+	Decoders decoders = decoder_factory (_film, options);
+	assert (decoders.audio);
+	
+	decoders.audio->set_audio_stream (_film->audio_stream ());
+	decoders.audio->Audio.connect (bind (&AnalyseAudioJob::audio, this, _1));
+
+	int64_t total_audio_frames = video_frames_to_audio_frames (_film->length().get(), _film->audio_stream()->sample_rate(), _film->frames_per_second());
+	_samples_per_point = total_audio_frames / _num_points;
+
+	_current.resize (_film->audio_stream()->channels ());
+	_analysis.reset (new AudioAnalysis (_film->audio_stream()->channels()));
+			 
+	while (!decoders.audio->pass()) {
+		set_progress (float (_done) / total_audio_frames);
+	}
+
+	_analysis->write (_film->audio_analysis_path ());
+	
+	set_progress (1);
+	set_state (FINISHED_OK);
+}
+
+void
+AnalyseAudioJob::audio (shared_ptr<AudioBuffers> b)
+{
+	for (int i = 0; i < b->frames(); ++i) {
+		for (int j = 0; j < b->channels(); ++j) {
+			float const s = b->data(j)[i];
+			_current[j][AudioPoint::RMS] += pow (s, 2);
+			_current[j][AudioPoint::PEAK] = max (_current[j][AudioPoint::PEAK], fabsf (s));
+
+			if (_done_for_this_point == _samples_per_point) {
+				_current[j][AudioPoint::RMS] = 20 * log10 (sqrt (_current[j][AudioPoint::RMS] / _samples_per_point));
+				_current[j][AudioPoint::PEAK] = 20 * log10 (_current[j][AudioPoint::PEAK]);
+				
+				_analysis->add_point (j, _current[j]);
+				
+				_done_for_this_point = 0;
+				_current[j] = AudioPoint ();
+			}
+		}
+		
+		++_done_for_this_point;
+	}
+
+	_done += b->frames ();
+}
+